Dipole antenna with u-shaped directors



Jan. 13, 1970 R. KOLBE ET AL DIPOLE ANTENNA WITH V-SHAPED DIRECTORS Filed Dec. 7. 1966 United States Patent F 4 ,88 Int. Cl. H01q 19/30 US. Cl. 343-819 7 Claims ABSTRACT OF THE DISCLOSURE An antenna arrangement in which an active dipole element has two dipole halves spaced from each other. Two sets of passive wave guides are mounted in front of the dipole halves, each set corresponding to one of the halves. The wave guides are electrically insulated from each other through insulators which are mounted on a central supporting bar. The wave guides are U-shaped and are secured to the insulators through their bases of the U shape. A radiating element interposed between the active dipole and the first ones of the passive wave guides, compensates against frequency dependent oscillations at the base of the antenna.

The present invention relates to an antenna arrangement having an active dipole element operating in conjunction with passive dipole elements situated within the radiation path.

Antenna arrangements of this species are especially applicable to television apparatus and ultrahigh frequency transmission. An important goal of these antenna arrangements is that they be designed so that their efiective regions be extended as widely as possible. This has been accomplished, heretofore, by mounting a plurality of complete Yagi antennas so that they are located next to each other and/or under each other. These antennas were then electrically connected and controlled together. Such an antenna arrangement, involving a plurality of antennas, incurs considerable expense with respect to materials and equipment. These arrangements also posses the inherent problem that the maximum extension of the effective antenna region, is realized when the individual Yagi antennas are separated from each other by a relatively large distance. As a result of such large separations, between antennas, undesirable side lobes arise with respect to the direction of the overall antenna arrangement. Although these side lobes are reduced when the separation between individual antennas are decreased, the effective region of the overall antenna arrangement is, thereby, sharply reduced. Under these conditions, therefore, an increase in the effective region of the antenna arrangement can be realized only through the introduction of additional individual antennas accompanied by additional cost. The introduction of such additional equipment is normally not practical for purposes of increasing the eitective region of an antenna arrangement, in the usual types of installations.

Accordingly it is an object of the present invention to provide an antenna arrangement designed to have a maximum effective region without resorting to the inclusion of a plurality of individual antennas.

Another object of the present invention is to provide an antenna arrangement, of the character described, whereby the maximum effective region corresponds to that obtainable with a plurality of Yagi antennas situated in an optimum manner with respect to each other.

Yet another object of the present invention is to provide "ice an antenna arrangement, as set forth, having an active dipole element operating in conjunction with passive dipole elements in the form of wave guides.

A further object of the present invention is to provide an antenna arrangement, as described, whereby the aforementioned results are achieved with a minimum amount of equipment.

A still further object of the present invention is to provide an antenna arrangement, as set forth, which operates reliably and may be maintained economically.

With the preceding objects in view, the present invention includes an energized active dipole element having two halves each associated with a plurality of wave guides corresponding to an active half-wave dipole. The wave guides associated with each half of the active dipole element, are separately situated and electrically isolated from the wave guides in the other half section. Such an antenna arrangement, according to the present invention, exhibits only a single energized dipole. In contrast to the usual Yagi antenna arrangement, the present invention does not provide for one or more rows of wave guides stemming from the middle of the dipole. Instead, the present invention provides for one or more of such rows with respect to each half of the dipole, whereby the wave guides possess that length that they would have if they served in conjunction with a half-wave dipole. Unlike an arrangement of individual Yagi antennas, the present invention achieved considerable increase in its effective region, in a practical manner, without the addition of considerable equipment and electrical connecting ele ments. The design associated with the present invention is considerably simpler, in almost every respect, when compared to the arrangement applying a plurality of complete individual antenna elements.

A further increase in the effective region of the antenna arrangement, according to the present invention, is achieved with the design whereby the wave guide associated with each half of the active dipole element, reside in two oppositely situated planes. Further simplification in the construction and assembly of the present invention is realized when the wave guides associated with each half of the active dipole element, are in the form of conductive elements. The latter are constructed in the form of U-shaped wires or conductors which are supported, at their bases, by a cross member made of insulating material. These cross members are, in turn, secured to a supporting rod. Only one such supporting rod is required for the entire arrangement, and the latter is especially applicable to high frequencies when the wave guides are formed from wire.

A particular advantage of an embodiment of the present invention occurs when the active dipole element is in the form of a full-wave dipole. This is due to the condition that improved coupling is realized between the dipole half and the associated rows of Wave guides. This arrangement provides a particularly desirable increase in the elfective region, when compared to the usual Yagi antenna. In order to compensate the antenna arrangement, according to the present invention, for the frequency dependent oscillation at the base, a rather simple element is introduced. An embodiment of the invention provides for the insertion of passive dipole elements between the full wave dipole and the first set of wave guides arranged along the supporting rod.

The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction, additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in conriection with the accompanying drawings, in which:

FIG. 1 is an isometric view showing the antenna construction and the relationship of the wave guides with respect to the full wave dipole;

FIG. 2 is an enlarged isometric view, and shows the manner in which two wave guides are secured to a cross member which is, in turn, mounted on a supporting rod shown in FIG. 1.

Referring to the drawings, and, in particular to FIG. 1, the antenna is essentially in the form of an energized full-wave dipole. Both halves of the latter are extended through conductive surfaces, for purposes of impedance matching. The full-wave dipole 1 is an active dipole element of the antenna, and is secured to a mounting rod 2. A reflector 3 in the form of a wire mesh screen, or grid, is also secured to this mounting rod 2, so that it intercepts substantially the main radiation.

As shown in FIG. 1, each half of the full-Wave dipole 1 is associated with one of two rows of wave guides situated in opposite planes. One row of these wave guides is designated by A, while the other row is designated as B. Each wave guide in each of the two rows A and B, is constructed as an active dipole element in the form of a half-wave dipole. By constructing the individual wave guide in the form of bar-shaped parasitic antenna elements, each wave guide becomes a half-wave dipole corresponding to the wave guides of a Yagi antenna. Each wave guide within the rows A and B, is mounted upon the rod 2, so that it is separately situated and electrically isolated. The individual wave guides in each row A and B, comprises substantially a U-shaped conducting wire 4 and 5, respectively. Adjacent conductive wire elements 4 and 5 associated with rows A and B, respectively are held and supported by the cross-member 6. The latter is made of non-conductive material and thus isolates the elements 4 and 5 from each other. The cross-member v6, is, in turn, supported upon the mounting rod 2. The formed wire elements 4 and 5 may :be secured to the cross member 6 by any one of the commonly known joining techniques. It is an essential condition of the arrangement that the individual wave guides be in the form of active dipole elements corresponding to wave guides of a half-wave dipole and that each row of wave guides corresponds to one-half of the full wave dipole l.

A passive dipole element in the form of a parasitic radiator 7 is mounted upon the supporting rod 2, be tween the full wave dipole 1 and the first pair of wave guide elements 4 and 5. The radiator 7 is electrically connected to the supporting rod 2, in a manner, similar to the prevailing in the usual types of wave guide arrangements. The radiator 7 serves the purpose of compensating for the frequency dependent oscillations at the base of the antenna arrangement.

While the invention has been illustrated and described as embodied in Wave guides for antenna arrangements, it is not intended to be limited to the details shown, since various modifications and structural changes may be made Without departing in any Way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be secured by Letters Patent is:

1. In an antenna arrangement, in combination, an active dipole element having two spaced dipole halves; two sets of passive wave guides, each of said sets composed of a plurality of passive wave guides located in series in front of one of said dipole halves spaced from each other and from the respective dipole halves, the passive wave guides of one of said sets being electrically insulated at least from the passive wave guides from the other of said sets, said passive radiation elements being each made of conductive material, and each being U-shaped; at least one insulating member for retaining each of said passive radiation elements; supporting means for supporting said insulating member, said insulating member being secured to said supporting means and insulating electrically said passive wave guides from said supporting means, said U-shaped passive wave guides being secured to said insulating member at the base of said U shape, said active dipole element being a full wavelength at the operating frequency.

2. In an antenna arrangement, in combination, an active dipole element having two spaced dipole halves; two sets of passive wave guides, each of said sets composed of a plurality of passive wave guides located in series in front of one of said dipole halves spaced from each other and from the respective dipole halves, the passive wave guides of one of said sets being electrically insulated at least from the passive wave guides from the other of said sets, said passive wave guides being U-shaped; at least one insulating member for retaining each of said passive wave guides; supporting means for supporting said insulating member, said insulating member being secured to said supporting means and insulating electrically said passive wave guides from said sup porting means, said U-shaped passive wave guides being secured to said insulating member at the base of said U shape so that the bases of said U shape of said two sets of wave guides lie oppositely on said insulating member with the open parts of the U facing in opposite directions.

3. An antenna ararngement as defined in claim 2 including radiating means secured to said supporting means and interposed between said active dipole and said passive. wave guide for compensating against frequency dependent oscillations.

4. An antenna arrangement as defined in claim 2 wherein the two sets of passive wave guides are arranged in oppositely residing planes.

5. An antenna arrangement as defined in claim 2 wherein said supporting means is an elongated barshaped member.

6. An antenna arrangement as defined in claim 5 wherein said insulating member is secured to said elongated bar-shaped member and retains two passive radiation elements each from a different one of said two sets of radiation elements, said two passive radiation elements being retained by said insulating member in a plane substantially perpendicular to said elongated barshaped member. a

7. An antenna arrangement as defined in claim 2 wherein said active dipole element is a full-wave dipole.

References Cited UNITED STATES PATENTS 3,092,835 6/1963 Iayjanie 343-817 3,277,491 11/1966 Liu 343-815 3,396,399 8/1968 Winegard 343815 ELI LIEBERMAN, Primary Examiner 

